This is a competitive renewal application for a training program to support 6 postdoctoral trainees (M.D. and/or Ph.D.) and 3 predoctoral students (M.D./Ph.D., or Ph.D.) per year with a strong emphasis on cell and molecular biology/immunology of gene therapy. The average training period for postdoctoral and predoctoral students will be 3 and 4 years, respectively. Twenty two well-established preceptors will provide extensive training in highly active as well as interactive research laboratories pursuing state of the art research on fundamental aspects of cellular, molecular biological, and immunological aspects of a variety of human diseases, and the prospects of developing novel gene therapy approaches for some of these disorders. All of the preceptors are housed in newly built or renovated spacious laboratories in 4 basic science departments, 3 clinical departments, and in two research centers, with several cross-appointments, in four adjoining buildings. Major strengths of the training program include a strong track record of research on gene transfer/gene therapy, peer-reviewed publications and extramural funding of the preceptors, and the existence of one of three NIH-designated National Vector Laboratories on campus. Ample opportunities for pursuing multi-disciplinary research exist due to active, ongoing scientific collaborations among various preceptors. A significant emphasis is placed to promote and foster the development of the next generation of biomedical researchers committed to scientific careers in academic medicine to become independent investigators who, in turn, will themselves be productive and competitive. A multi-pronged approach for comprehensive training encompassing close and direct contact with preceptors, frequent, informal interactions with staff members, visiting scientists, formal and informal courses and seminars, laboratory meetings, and participation in national and international scientific meetings, is already in place and will be further emphasized. The decision to associate with a laboratory will be by mutual consent of the trainee and the preceptor, and the scientific development of the trainee will be facilitated by a research committee composed of preceptors with multi-disciplinary research interests. Major resources that are available include internationally recognized clinical and basic science research programs, state of the art infra-structure, and frequent contacts with active investigators at Indiana University in Bloomington, Purdue University in West Lafayette, and Eli Lilly and Company in Indianapolis, all in close proximity, and other investigators nationally as well as internationally.